Rope tension measuring device



Feb. 24, 1948. o. D. SYMMES ROPE TENSION MEASURING DEVICE Filed lay 31, 1943 Patented Feb. 24, 1948 ROPE TENSION MEASURING DEVICE Daniel D. Symmes, West Haven, Conn., assignor to The American Steel and Wire Company 01' New Jersey, a corporation of New Jersey Application May 31, 1943, Serial No. 489,215

2 Claims. 1

This invention is a new mechanical movement, incorporated in the design of a mechanical force measuring device where it functions to simplify the measurement of forces.

A specific example-oi the invention is illustrated by the accompanying drawing.

More specifically, this drawing shows a draft band i cooperating with a rocking draft band sector 2 iulcrumed, at I, eccentrically to provide a variable lever arm length for the draft band upon displacement. As illustrated, the sector I has its working surface in the form of an arc about the center 4 which is laterally offset from the fulcrum 3, the eflective lever arm length being defined by a line tangent the sector are at the point the draft band initially contacts this are, and a parallel line passing through the 1111- crum 3, these lines approaching one another with increasing displacement of the sector I by the draft band i, and the effective lever arm length consequently decreasing.

The movement described has the advantage that it is possible to have a force source connected with the sector, to react with its displacing force, which provides increasing force with increasing displacement, without necessitatin excessive displacement of this force source as is ordinarily required when the force, working the draft band i, varies greatly in amount.

In the case oi. the device disclosed, the abovedescribed force source comprises a. lever B, fulcrumed at 3, and connecting with the sector 2, so the two are displaced together, the swinging end of the lever 5 having a weight 9. The arrangement is such that the lever arm 5 approaches a vertical position when the draft band I is unloaded, and swings towards a horizontal position upon displacement of the sector 2 by loading of the draft band I. this resulting in increasing the effective lever arm defined between 9. vertical line passing through the fulcrum I and a vertical line passing through the center of gravity of the weight 8. it being obvious that this lever arm will increase as the lever I swings towards a horizontal position, with a consequent 45 increase in the force applied the draft band sector 2. The force supplied the draft band i may be measured by a hand I playing on a suitably calibrated dial 9 and turned by a pinion 9 engaged b a gear sector It that is displaced with the sector 2 and lever B.

In the case of the example illustrated. the draft band i is worked by a lever system H which is, in turn, worked by a sheave I! which engages and deflects a wire rope l3. In this instance it is desired to measure the tension on the rope It. The lever system Ii being arranged to multiply the movement imparted the draft band i by the sheave i2, and the dial 9 being suitably alibrated for the purpose in mind. Obviously it is not necessary to make this dial read in any particular fashion providing it conveys the desired information.

I claim:

1. A rope tension measuring device comprising a sheave adapted to engage a rope the tension 01' which is to be measured, a motion multiplying lever system including a bell crank, a lever pivoted intermediate its length, a link connecting the long arm of the bell crank to one end of the lever, the lever being substantially parallel with the long arm of the bell crank, said sheave being pivoted on the short arm of the bell crank, a. micrumed cam sector, a flexible band having one end attached to the cam sector and the other end to the free end of the lever, a weighted pendulum connected with the sector to apply force to the band and to provide an increasing force with increasing displacement, and means for indicating the amount of displacement of the sector.

2. A rope tension measuring device, comprising a member adapted to engage a rope whose tension is to be measured, a motion multiplying lever system including a bell crank having a long and a short arm, a lever pivoted intermediate its ends, means connecting the long arm of the bell crank to one end of the lever, said member being carried by the short arm of the bell crank, a fulcrumed cam sector, a flexible band attached at one end to the cam sector and the other end to the free extremity of the lever, a weighted pendulum connected with a sector to apply force to the band and to provide an increasing force with increasing displacement, and means for indicating the amount 01. displacement of the sector.

DANIEL D. BYMIVIES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 999,339 Reeves Aug. 1, 1911 1,414,764 Wistoft May 2, 1922 1,811,831 King June 23, 1931 1,211,820 Burbank Jan. 9, 1917 1,469,280 Stahl Oct. 2, 1923 1,987,815 Bartol Jan. 15, 1935 2,092,439 Bouhuys Sept. 7, 1937 FOREIGN PATENTS Number Country Date 203.703 Great Britain Oct. 9, 1921 

